Process and apparatus for severing sheet-glass



H. G. SLINGLUFF.

PROCES S AND APPARATUS FOR SEVERING SHEET GLASS.

APPLICATION FILED APRfIZ. 1920.

Patented Apr. 5, 1921.

@MMM .7 UNITED. S A E PATENT oFFicE.

HARRY G. SLINGLUFF, OF MOUNT VERNON, OHIO, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA.

. iROCESS AND; APPARATUS FOR SEVERING SHEET-GLASS.

. Specification of Letters Patent.

Patented Apr. 5, 1921.

' I Application filed April 12, 1920. Serial No. 373,211.

To all to from it may concern:

Be it knowntha't I, HARRY G. SLINGLUFF, a citizen of the United'S tates, and a resident of Mount Vernon, in the county of Knox and State of Ohio, have made a new and, useful Invention in Processes and Ap paratus for Severing Sheet-Glass, of which the following is a specification.

The invention relates to a process and apparatus for severing a continuously formed sheet of glass. It has. for its principal objects, the provision of an improved severing means which will completely heat the glass on a line extending from one side of the sheet to the other without interruption; the provision of an improved device of the character specified, in which arrangement is made for the movement of the device with the sheet of glass; and the pro- .vision of a device which can be conveniently and rapidly operated and. which will insure the ready severance of the sheet along the desired line, even though the sheet is not perfectly flat and even though condition of strain exists in the lass which would otherwise prevent its proper cutting off by the use of the usual severing means such as a diamond or cutting wheel. Qne embodiment of the invention is illustrated in the accompanying drawings, wherein:

Figure l is a horizontal section through the apparatus upon the line 11 of Fig. 2. Fig. 2 is a side elevation and Fig. 3 is an enlarged vertical section through the glass sheet and the heating or cracking off bars.

, As shown in 1 and 2, l is a glass sheet which is being continuously generated members 5-5. These pairs of strap iron members are supported by U members 6-6 connected by wires 7 to counterweights 8 to assist in the upward movement of the crackiron members 5-5.

ing off members. The U members 6-6 have their lower ends perforated to receive the studs 99, and provision is made for movement of the U member longitudinally of the studs as indicated in Fig. 1, so that the bars 4:t are free to move toward and from each other to engage the glass and be disengaged therefrom as hereinafter set forth.

The channel bars 4-4; are provided upon their inner sides with the asbestos strips 10 10, as indicated in Fig. 8, and mounted upon the inner faces of these strips are resistance bands 1111 preferably made of nichrome. One end of each of these bands 11-11 is secured fixedly. by means of the bolts 12 (Fig. 1), while the other ends are preferably secured to spring members 13 for the purpose of keeping the strips 11 under tension, the preferred arrangement as to matters of detail at this part of the device being shown and described in the Hitner PatentNo. 1,296,661 of March 11th, 1919,

and forming no part of the present inven tion.

In order to move the cracking off bars toward each other to bring the strips ll into contact with the opposite sides of the glass, electro-magnets 141et are employed, provision being made for supplying current to the windings by suitable means not illustrated, and including switches either hand or automatically operated for making and breaking the circuit. In order to separate the cracking off bars after the circuit is broken, the springs 1515 are employed, such springs hearing at their inner ends upon the sleeve'member 16, in which are guided the pins 17-17carried by the strap In order to restrict the relative movement of the members 5-5, chains'or other flexible connecting devices "18 are employed, such members preventing approach so that the nichrome bands 11 en- 1 gage the opposite sides of the sheet. The

bars then move upward with the sheet which is being generated, the weight lifted being reduced by reason of the counterweights 8,

so that no undue strain is thrown upon the glass. At this time current is passed through the nichrome bands, causing them to attain a high temperature and heat the area of glass lying between the two bands. This contact is maintained a period of time, such as experience indicates is necessary, at which time the circuit through the electromagnet windings is broken, causing the release of the bars a from the glass, and at this time some point upon the line of heating of the glass is cooled. This may be done by applying a little moisture or by blowing cold air upon the line of heating of the sheet, which causes the sheet to crack trans versely upon the line of heating. A great advantage is found in heating both sides of the sheet by the use of the two bands as opposed to heating by one band only, since the heating as produced by the two bands is more rapid and complete, even where the sheet is perfectly fiat, and in cases where the sheet is not perfectly flat, one of the bands 11 will touch opposite those points at which the other band does not contact. The sheet of glass is thus heated across its entire width so that a proper severing is secured when moisture or cold air is applied to the line of heating. When the current through the magnet windings is interrupted the springs 15 cause the immediate separation of the bars d l and the device moves downward to the position indicated in Fig. 2, the weight of the devices being just sufiiciently greater than the weight of the counterweights to cause this downward movement and bring the parts to the starting position. No means has been shown for making and breaking the circuit through the magnet windings as this is a mere matter of detail having nothing to do with the broad invention. Similarly as to the application of the devices for making the operation more or less automatic if it should be desired to do so." The advantages incident to the invention and the possibility of embodying it in a .wide variety of forms to meet different conditions willbe readily apparent to those skilled in the art.

What I claim is: 1. A processof severing a continuously formed sheet of glass which consists in applying a pair of electrically heated transversely extended members to the opposite sides of the sheet at the same time.

2. A process of severing a continuously formed sheet of glass which consists in clamping a pair of transversely extending opposed electrically heated members to the opposite sides of the sheet at the same time so that said members are moved along by the sheet, and releasing said members when the glass between the two members is sufiiciently heated for cracking off.

3. An apparatus for severing a continuously formed sheet of glass, a pair of opposed bars extending transversely on opposite sides of the sheet to be severed, electrically heated members extending longitudinally of the bars, and means for clamping the bars to the sheet so that the bars move along with the sheet.

al. An apparatus for severing a continuously formed sheet of glass, a pair. of opposed bars extending transversely on opposite sides of the sheet to be severed, electrically heated members extending longitudinally of the bars, and electro-magnetic means carried by the bars at their ends for clamping the bars together with the sheet gripped between them, so that the bars move forward with the sheet.

5. An apparatus for severing a continuously formed sheet 01": glass, a pair of opposed bars extending transversely on opposite sides of the sheet to be severed, electrically heated members extending longitudinally of the bars, yielding means normally pressing the bars apart, and electro-magnetic means carried by the bars at their ends for overcoming the yielding means and causing the bars to approach and grip the sheet between the electrically heated members.

6. An apparatus for severing a continuously formed sheet of glass, a pair of transversely extending electrically heated means on opposite sides of the sheet, means for causing said members to approach and grip the sheet between them, and means for causing the separation of the members after the glass lying therebetween is sufiiciently heated.

In testimony whereof, I have hereunto subscribed my name this 6th day of ApriL.

HARRY G. SLINGLUFF. 

